1. Field of the Invention
The present invention generally relates to a light-emitting module with a cooling function and, more particularly, to a light-emitting module equipped with a heat sink for cooling purposes.
2. Description of the Related Art
Referring to FIG. 1, Taiwanese Patent No. 1316121 discloses a conventional lamp 8 with a housing 81. The conventional lamp 8 consists of an air outlet portion 811 and an air inlet portion 812. The housing 81 receives a light-emitting module 82 with a cooling function that consists of a heat sink 821, a light-emitting element 822 and a cooling fan 823. The light-emitting element 822 and the cooling fan 823 can be coupled with the heat sink 821. Based on the structure, the cooling fan 823 may draw air into the conventional lamp 8 via the air inlet portion 812. The drawn air will flow past the heat sink 821 and be expelled via the air outlet portion 811. Utilization of the heat sink 821 can facilitate dissipating the heat generated by the light-emitting element 822 and can increase service life of the light-emitting element 822.
The light-emitting element 822 of the light-emitting module 82 is usually coupled with the heat sink 821 for cooling purposes. Due to a variety of shapes and sizes available for the light-emitting element 822, however, different light-emitting element 822 should be mounted on different heat sinks 821 whose assembling holes are aligned with the assembling holes of the light-emitting element 822 for assembly purposes. Therefore, different molds should be prepared to manufacture different heat sinks 821 for all kinds of light-emitting elements 822, leading to an increased cost.
FIG. 2 shows another conventional light-emitting module 9 with a cooling function. The conventional light-emitting module 9 has a light-emitting element 91 mounted on a heat sink 93 via a connection board 92. In this arrangement, the connection board 92 is disposed between the light-emitting element 91 and the heat sink 93. The connection board 92 has a plurality of assembling holes 921 that must be aligned with a plurality of assembling holes 931 of the heat sink 93 for assembling purposes. In this regard, when it is desired to mount another light-emitting element 91 with a different shape and size on the heat sink 93, the only component that should be changed is the connection board 92 rather than the heat sink 93 (note the assembling holes 921 of the new connection board 92 have to align with the assembling holes 931 of the heat sink 93 for assembly purposes). This mechanism allows different light-emitting elements 91 to be assembled to the heat sink 93 without making a new mold for the heat sink 93 as required by the conventional lamp 8. Since the connection board 92 has a much lower cost than the heat sink 93, the cost of the conventional light-emitting module 9 can be significantly reduced.
However, the heat generated by the light-emitting element 91 cannot be efficiently delivered to the heat sink 93, because the light-emitting element 91 is indirectly mounted on the heat sink 93 via the connection board 92. As a result, the cooling effect is limited. Furthermore, since a heat-conducting medium 94 such as a thermal paste can be arranged between the light-emitting element 91 and the heat sink 93 for better heat conduction, both faces of the connection board 92 should be coated with the heat-conducting medium 94, and an increased cost, therefore, results resulted.